You may have already done this research, but I feel like talking about it. The Mask in the original comics was simply a magic mask of unknown origin that not only gives it's wearer power over reality within a sphere of influence; but also suppresses the ego and the super-ego of the individuals personality, turning them into a being that uses his powers only to serve his own selfish desires. (ex: The comic's Stanley Ipkiss used the mask's power to murder everyone that was ever an asshole to him.) In the film and animated series; the Mask rather than rendering the ego and super-ego inert, merely makes them weaker thus leaving a benevolent wearer still benevolent but still very self serving.